What were the first organisms to have sex? We may never know the answer, but as Bill Nye explains in this Big Think interview, scientists are very interested in why sexual activity remains so popular in nature...

Manhattanhenge

Neil deGrasse Tyson snapped this photograph of the Mahattanhenge, an event that occurs twice a year when the city's grid takes on the special effects of Stonehenge. This Saturday, if you're in New York, catch the sun's light flood the city as it sets.